Should I become a vegetarian?

Dear Economist,
A growing trend among my fellow students is converting to vegetarianism for environmental reasons, citing statistics that meat production, in particular beef, is a tremendous cause of greenhouse gas emissions. I was wondering if you could provide some insight into the actual environmental cost of a steak. How does it compare to driving, or flying? Would a simple tax on beef production be much more efficient than vegetarianism?
Max

Dear Max,

Your friends are right to worry about beef; you are right to ask questions. Let’s start with the beef itself. Cows are ruminants, which means they produce large quantities of methane – contrary to what some people believe, much of this is emitted through the mouth. Methane is a powerful but transient greenhouse gas, so it is not straightforward to compare with carbon dioxide emissions, especially those produced by planes at altitude, which are more damaging.

Using a standard rule of thumb – and the work of “Economical Environmentalist“ Prashant Vaze – I can inform you that a 250g steak is responsible for more than 4kg of CO2-equivalent emissions, before cooking the stuff.

Sheep is just as bad; pork and chicken are half as bad; cod or wheat are at least eight times less carbon-intensive; potatoes and herring are far better still. Organic methods reduce carbon dioxide emissions, but not by much.

Yet this all looks modest relative to the costs of transport. Vaze reckons that steak’s emissions will get you about eight miles by plane, or 15 miles if you travel alone in a car.

As for the tax, it should be on all greenhouse gases, not just cow burps. I suspect it would create a few vegetarians, perhaps better diets for cows, and headaches for the taxman. More importantly, it would inspire some loft insulation.